Patent application number | Description | Published |
20080232030 | Wet electrolytic capacitor containing a plurality of thin powder-formed anodes - A wet electrolytic capacitor that includes a plurality of anodes, cathode, and working electrolyte that is disposed in electrical contact with the anodes and current collector is provided. Any number of anodes may generally be employed, such as from 2 to 40, in some embodiments from 3 to 30, and in some embodiments, from 4 to 20. The anodes are thin and typically have a thickness of about 1500 micrometers or less, in some embodiments about 1000 micrometers or less, and in some embodiments, from about 50 to about 500 micrometers. By employing a plurality of anodes that are relatively thin in nature, the resulting wet electrolytic capacitor is able to achieve excellent electrical properties. For example, the equivalent series resistance (“ESR”)—the extent that the capacitor acts like a resistor when charging and discharging in an electronic circuit—may be less than about 1500 milliohms, in some embodiments less than about 1000 milliohms, and in some embodiments, less than about 500 milliohms, measured with a 2-volt bias and 1-volt signal at a frequency of 1000 Hz. | 09-25-2008 |
20090244812 | Hermetically Sealed Capacitor Assembly - A capacitor assembly that includes a conductive polymer electrolytic capacitor that is enclosed and hermetically sealed within a ceramic housing in the presence of an inert gas is provided. Without intending to be limited by theory, the present inventors believe that the ceramic housing is capable of limiting the amount of oxygen and moisture supplied to the conductive polymer of the capacitor. In this manner, the conductive polymer is less likely to oxidize in high temperature environments, thus increasing the thermal stability of the capacitor assembly. | 10-01-2009 |
20100047683 | ELECTROCHEMICAL ENERGY STORAGE DEVICE - Apparatus and methodology subject matters relate to an improved electrochemical single or multi-cell energy storage device. Also, an outer casing may be provided as a pair of U-shaped shells, a single foil piece, or a tube-shaped structure which encases the internal electro chemical cell stack. The energy storage device and such casing when used advantageously exhibit low internal resistance, low ESR, a high voltage/capacity, and a low contact resistance between the internal stack and the outer casing. | 02-25-2010 |
20100067174 | Substrate for Use in Wet Capacitors - A porous substrate for use in a wide variety of applications, such as wet capacitors, is provided. The substrate is formed by subjecting a metal substrate to a voltage while in solution to initiate anodic formation of an oxide film. Contrary to conventional anodization processes, however, the newly created oxide quickly breaks down to once again expose the metal surface to the electrolytic solution. This may be accomplished in a variety of ways, such as by raising the voltage of the solution above a critical level known as the “breakdown voltage”, employing a corrosive acid in the solution that dissolves the oxide, etc. Regardless of the mechanism employed, the nearly simultaneous process of oxide growth/breakdown results in the formation of a structure having pores arranged at substantially regular intervals. The resulting structure is highly porous and can exhibit excellent adhesion to electrochemically-active materials and stability in aqueous electrolytes. | 03-18-2010 |
20100142123 | Electrochemical Capacitor Containing Ruthenium Oxide Electrodes - A capacitor containing an electrochemical cell that includes ruthenium oxide electrodes and an aqueous electrolyte containing a polyprotic acid (e.g., sulfuric acid) is provided. More specifically, the electrodes each contain a substrate that is coated with a metal oxide film formed from a combination of ruthenium oxide and inorganic oxide particles (e.g., alumina, silica, etc.). Without intending to be limited by theory, it is believed that the inorganic oxide particles may enhance proton transfer (e.g., proton generation) in the aqueous electrolyte to form hydrated inorganic oxide complexes (e.g., [Al(H | 06-10-2010 |
20100142124 | Cathode for Use in a Wet Capacitor - A cathode containing a metal substrate that possesses a micro-roughened surface imparted by spark anodization is provided. The surface is formed by contacting the substrate with an electrolytic solution and applying a voltage to form a dielectric sub-oxide layer. The voltage is raised to a sufficiently high level to initiate “sparking” at the surface of the substrate, which is believed to create high local surface temperatures sufficient to etch away the substrate. This results in the formation of a “micro-roughened” surface having a plurality elevated regions. These elevated regions can increase the effective surface area and thus allow for the formation of capacitors with increased cathode capacitance for a given size and/or capacitors with a reduced size for a given capacitance. The elevated regions may also exhibit excellent adhesion to additional electrochemically-active materials and provide enhanced stability in certain liquid electrolytes. | 06-10-2010 |
20100238606 | Electric Double layer Capacitor - An electric double layer capacitor that contains at least one electrochemical cell is provided. The cell contains electrodes (e.g., two electrodes) that each contain a porous matrix of electrochemically-active particles (e.g., carbon). An aqueous-based electrolyte is disposed in contact with the porous matrix. In accordance with the present invention, the electrolyte is provided with an anionic polymer that serves as binding agent for the electrochemically active particles and thus reduces electrolyte loss, especially at higher temperatures. Because the polymer is anionic in nature, it is generally hydrophilic and thus can retain its binding properties in the presence of water. The anionic nature of the polymer also allows it to remain stable in the presence of a corrosive polyprotic acid, which is employed in the electrolyte to enhance charge density. Thus, as a result of the present invention, a capacitor may be formed that is capable of exhibiting good electrical performance (e.g., high capacitance and low ESR), even at high temperatures (e.g., 70° C. and above). | 09-23-2010 |
20120113567 | Hermetically Sealed Capacitor Assembly - A capacitor assembly that includes a conductive polymer electrolytic capacitor that is enclosed and hermetically sealed within a ceramic housing in the presence of an inert gas is provided. Without intending to be limited by theory, the present inventors believe that the ceramic housing is capable of limiting the amount of oxygen and moisture supplied to the conductive polymer of the capacitor. In this manner, the conductive polymer is less likely to oxidize in high temperature environments, thus increasing the thermal stability of the capacitor assembly. | 05-10-2012 |